I have a 2006 Ford F250 Powerstroke 6.0. I just had ARP head studs, new head gaskets, upgraded oil cooler, EGR Delete kit, new injector O-rings on the factory injectors, and a new powermax turbo. I also had SCT tuner build me 3 custom tunes which are, extreme street, extreme towing, & fuel economy. Before all of this my truck was getting great fuel mileage, 18 mpg on average on the highway. Now I'm getting 11mpg at best no matter which tune I run it on. Any ideas to make fuel mileage better?

 

how long ago was all the work done??

how long since filters were changed?

 

All work mentioned done 1 week ago. Oil changed last week, fuel filters changed yesterday.

 

Are you sure this isn't just your right foot being overly happy with the new mods?

How are you checking mileage? I hope you're not going off of the lie-o-meter on the dash. What size tires, what size gears? How many tanks have you run to check?

 

You need to drive it more. PCM relearning takes longer then you think.

Were you tuned prior to the mods???

 

I just had the same thought Heavy..

Are these new tunes from before or after all this work? Did you get tunes written for the new mods?